They make some covers that go under the floor board and will protect the floor boards from rocks and sticks .....
The plastic skid plates that come stock suck ..... I cracked mine in the first few days .....
HCR makes some nice stock replacment skid plates made out of aluminum for the front and rear at a good price .... they are great if you dont want to buy the whole skid plate package ..... I think the rear is $ 50.00 and the front is $ 75.00 ........ they usually list them on Ebay ....